hétfő tevékenység Elrontott storm drain wiki Kísértés Nem nélkülözhetetlen erős
Maybe it is to provide a way for air to escape from a storm drain to prevent an [air lock](https://en.wikipedia.org/wiki/Air_lock) in the storm drain pipes. [...] : r/thisisthatthing
Highway drainage - Designing Buildings
File:Aliso storm drain.JPG - Wikipedia
Infiltration trenches - LID SWM Planning and Design Guide
Storm drain - Wikipedia
Drawings - LID SWM Planning and Design Guide
File:Storm sewer and catch basin.jpg - Wikimedia Commons